In response to the increasing demand to lower the level of water consumption, various low water dishmachines have been developed that are designed to use up to half the amount of water as conventional dishmachines. While the low water dishmachines effectively reduce the amount of water used during dishwashing cycles, the lower sump volumes and final rinse volumes lead to increased soil accumulation in the sump of the new water-saving dishmachines. For example, if the amount of rinse water is cut in half, the amount of soil in the sump doubles in concentration. As the water in the sump is recirculated within the dishmachine, filming on the ware being cleaned in the dishmachine can occur due to the food soil accumulation in the sump.
Hydrocyclones are well known in the waste water industry for separating solids from solution. Because hydrocyclones have no moving parts or filter screens, they require minimal maintenance. In the waste water industry, hydrocyclones are currently used in undercounter dishmachines to remove particles having a density higher than a pre-determined amount. While hydrocyclones are effective at removing gross food soils (i.e., food pieces such as lettuce), they may not be as effective at removing smaller suspended food particles (i.e., particles less than 2 millimeters (mm) and more particularly less than 1 mm in size).
There is therefore a need for a method for reducing the amount of food soil and more particularly, food soil particles, in recirculated wash solutions.